VCONN in power delivery chargers

ABSTRACT

A circuit comprising a first processing element having a first output configured to couple to a voltage control circuit, a second output configured to couple to a gate terminal of a first transistor, and a third output configured to couple to a first node and a control circuit. The control circuit comprises a second processing element having multiple outputs, a second transistor having a gate terminal configured to couple to one of the outputs of the second processing element, a first terminal configured to couple to a second node and to a drain terminal of the first transistor, and a second terminal, and a third transistor having a gate terminal configured to couple to a second of the outputs of the second processing element, a first terminal configured to couple to a third node, and a second terminal.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Division of U.S. patent application Ser. No.16/044,250 filed Jul. 24, 2018 (currently U.S. Pat. No. 10,990,150issued Apr. 27, 2021).

BACKGROUND

Universal Serial Bus (USB) is a standard that specifies specificationsfor USB cables and communications protocols for communicating dataand/or power between at least two USB capable devices. Multiplespecifications exist for various types of USB cables and their attendantcapabilities. Some of these types include USB type-A (USB-A), USB type-B(USB-B), USB type-C (USB-C), and others. As technology progresses andthe capabilities of various types of USB cables and their capabilitiesincreases, the USB cables may advertise or otherwise inform connecteddevices of the capabilities of the USB cables, thereby leading to areasof potential optimization, improvement, or change in the interactionbetween USB cables and devices to which they are coupled or configuredto couple.

SUMMARY

Aspects of the present disclosure provide for a circuit comprising afirst processing element having a first output configured to couple to avoltage control circuit, a second output configured to couple to a gateterminal of a first transistor, and a third output configured to coupleto a first node and a control circuit. The control circuit comprises asecond processing element having multiple outputs, a second transistorhaving a gate terminal configured to couple to one of the outputs of thesecond processing element, a first terminal configured to couple to asecond node and to a drain terminal of the first transistor, and asecond terminal, and a third transistor having a gate terminalconfigured to couple to a second of the outputs of the second processingelement, a first terminal configured to couple to a third node, and asecond terminal.

Other aspects of the present disclosure provide for a system. The systemcomprises a power supply having an output coupled to a first node, avoltage control circuit having a first input coupled to the first node,a second input, and an output, a first processing element having a firstoutput coupled to the second input of the voltage control circuit, afirst input coupled to the output of the voltage control circuit, asecond output coupled to a second node, and a third output, a firsttransistor having a gate terminal coupled to the third output of thefirst processing element, a first terminal coupled to the first node,and a second terminal coupled to the second node, and a control circuithaving an input coupled to the first node, a first output coupled to athird node, and a second output couple to a fourth node. The systemfurther comprises a Universal Serial Bus (USB) plug receptaclecomprising a first bus voltage (VBUS) terminal coupled to the secondnode, a first configuration channel (CC1) terminal coupled to the thirdnode, and a second configuration channel (CC2) terminal coupled to thefourth node and a USB cable. The USB cable comprises a USB plugcomprising a second VBUS terminal configured to couple to the first VBUSterminal, a CC terminal configured to couple to one of the CC1 terminalor the CC2 terminal, a connector voltage (VCONN) terminal configured tocouple to another of the CC1 terminal or the CC2 terminal, and anelectronic marker (e-marker) coupled to the VCONN terminal, wherein thecontrol circuit is configured to couple the e-marker to the first nodevia one of the CC1 terminal or the CC2 terminal and the VCONN terminal.

Other aspects of the present disclosure provide for a method, comprisingdetecting, by a controller, a coupling from a sink device to a sourcedevice, applying, by the controller, a signal to a bus voltage (VBUS)terminal and a connector voltage (VCONN) terminal of a cable performingthe coupling, communicating, by the controller, with the cableperforming the coupling to determine characteristics of the cable,removing, by the controller, the signal from the VCONN terminal,communicating, by the controller, with the sink device at leastpartially according to the characteristics of the cable, and increasing,by the controller, a value of the signal provided to the VBUS terminalbeyond an acceptable limit for providing to the VCONN terminal.

Communication with active USB cables often involves separatehigh-voltage and low-voltage power supplies, increasing the cost andsize of a system communicating with the active USB cable. A value of thehigh-voltage power supply may be too large for the high-voltage powersupply to replace the low-voltage power supply in operation at alltimes. When the high-voltage power supply has a variable output capableof providing both the low-voltage and the high-voltage, the high-voltagepower supply may be configured to provide both the high-voltage andlow-voltage. However, the high-voltage supply may cause damage when thehigh-voltage supply is providing the high-voltage and is coupled to aterminal configured to receive the low-voltage. To at least partiallymitigate this problem, a controller may monitor the output of thehigh-voltage power supply and selectively couple, or decouple, thehigh-voltage power supply from the terminal configured to receive thelow-voltage when certain conditions are met.

BRIEF DESCRIPTION OF THE DRAWINGS

For a detailed description of various examples, reference will now bemade to the accompanying drawings in which:

FIG. 1 shows a block diagram of an illustrative system in accordancewith various examples;

FIG. 2 shows a schematic diagram of an illustrative circuit inaccordance with various examples;

FIG. 3 shows a schematic diagram of an illustrative circuit inaccordance with various examples;

FIG. 4 shows a schematic diagram of an illustrative circuit inaccordance with various examples;

FIG. 5 shows a schematic diagram of an illustrative circuit inaccordance with various examples;

FIG. 6 shows a timing diagram of illustrative signals in accordance withvarious examples; and

FIG. 7 shows a flowchart of an illustrative method in accordance withvarious examples.

DETAILED DESCRIPTION

Universal Serial Bus (USB) cables referred to herein include at leastone plug, a paddle card configured to provide processing capabilities,and a one or more electrically conductive or optically transmissivewires. Some USB paddle cards (e.g., such as USB-C paddle cards) includean electronic chip referred to as an electronic marker (e-marker)capable of communicating with devices to which the USB paddle card iscoupled. Devices to which the USB paddle card is coupled, in someexamples, query the e-marker to determine capabilities of the USB cable.The capabilities may include any specifications, operational limits, orother information related to, or potentially useful in, utilizing theUSB cable. At least one example of such a capability communicated by thee-marker is a maximum current rating of the USB cable (e.g., the amountof current that the USB cable can carry without suffering damage and/ora lack of fidelity in a data transfer involving the USB cable). Tocommunicate with the e-marker, a device coupled to the USB paddle cardprovides a signal having a voltage between approximately 3 volts (V) andapproximately 5V to a connector voltage (VCONN) terminal of the USBpaddle card to activate the e-marker. To provide the 5V signal, it iscommon, and sometimes required, to include a low-voltage supply withinthe device communicating with the USB paddle card. In somecircumstances, this low-voltage supply may serve no other purpose in thedevice communicating with the USB paddle card and exists solely forcommunication with USB paddle cards to activate e-markers forcommunication. In such circumstances, the low-voltage supply mayincrease the size, complexity, cost of manufacture, cost of operation,and/or other undesirable characteristics of the device communicatingwith the USB paddle card.

One option for elimination of the dedicated low-voltage supply is toutilize an existing signal passing through the USB paddle card foractivating the e-marker, for example, such as a signal present at a busvoltage (VBUS) terminal of the USB paddle card. However, in modern USBstandards, such as USB-C, the VBUS terminal may at times have voltagesgreater than 5V (or 5V plus an over-voltage tolerance level of thee-marker), which if applied to the e-marker might damage and/or destroythe e-marker. For example, when the USB cable is utilized as a chargingcable, a signal having a voltage of up to approximately 20V or greatermay be present at the VBUS terminal.

At least some aspects of the present disclosure provide for a circuitenabling powering of a VCONN terminal of a USB paddle card utilizing aVBUS signal while preventing a voltage present at the VCONN terminal ofthe USB paddle card from exceeding a predefined voltage level (such as5V), or the predefined voltage level plus an associated over-voltagetolerance. In some examples, the circuit is implemented in a PowerDelivery (PD) Controller (e.g., a USB PD controller of a deviceconfigured to couple to a USB paddle card). In other examples, thecircuit is implemented as a standalone component configured to couple toa PD Controller and/or a USB paddle card. In at least one example, thedisclosed circuit monitors a VBUS voltage level and toggles a switch tocouple (or decouple) the VBUS signal to (or from) the VCONN terminal ofthe USB paddle card based on the VBUS voltage level. In some examples,the determination of whether to couple (or decouple) the VBUS signal to(or from) the VCONN terminal of the USB paddle card is further based onwhether the device including the circuit is attempting, or will attempt,to activate and/or communicate with an e-marker of the USB paddle card.In at least some examples, the circuit includes one or more switches anda microcontroller configured to perform the monitoring and control theone or more switches to perform the coupling (or decoupling) of the VBUSsignal to (or from) the VCONN terminal. The switches can be any suitableswitching mechanism including field effect transistors (FETs) such asmetal oxide FETs (MOSFETs), bi-polar junction transistors (BJTs),mechanical switches such as relays, or any other suitable switchingtechnology and/or architecture.

Referring now to FIG. 1, a block diagram of a USB system 100 is shown.In one example, the USB system includes a source device 102, a USB cable104, and a sink device 106. The source device 102, in at least oneexample, is a device providing a signal to the sink device 106 via theUSB cable 104 such that the sink device 106 pulls current from thesource device 102 via the USB cable 104. In at least some examples, thesource device 102 includes a power supply 108, a USB PD controller 110,and a voltage control circuit 112. The power supply 108 is a powersupply capable of providing an output signal with an adjustable voltagelevel that is adjusted, for example, based on a control signal receivedby the power supply 108. In at least some examples, the power supply 108receives the control signal from the voltage control circuit 112. Insome examples, the power supply 108 receives the control signal from thevoltage control circuit 112 via optical communication (e.g., anoptocoupler), while in other examples the power supply 108 receives thecontrol signal from the voltage control circuit 112 via a physicalcoupling between the power supply 108 and the voltage control circuit112. In other examples, the power supply 108 itself is not adjustable,but an external component coupled, or configured to couple, to an outputof the power supply 108 adjusts a value of a signal output by the powersupply 108. For example, the power supply output may be a signal havinga substantially constant voltage value that is manipulated to output oneor more other signals having different voltage values than the powersupply output. For example, the power supply output may be manipulatedby a power converter (not shown), such as a buck converter, a boostconverter, or a buck-boost converter, and an output of the powerconverter may be provided to the node 118. In at least some examples,the power converter is controlled by the voltage control circuit 112 tomanipulate the power supply output to form the one or more othersignals. The USB PD controller 110, in at least one example, is amicrocontroller having processing capabilities. In other examples, theUSB PD controller 110 is any processing element capable of receiving oneor more inputs and generating one or more outputs based on rules,analysis, or other processing applied to at least some of the inputs.

The voltage control circuit 112 is any circuit capable of regulatingand/or controlling a value of the signal that is present at node 118.For example, the voltage control circuit 112 is any circuit capable ofreceiving a reference voltage (VREF) from the USB PD controller 110 andcontrolling power supply 108 according to VREF to control the value ofthe signal present at node 118. For example, the voltage control circuit112 controls the power supply 108 according to VREF to cause the signalpresent at node 118 to have a value approximately equal, proportional,or otherwise having a relationship to a value of the reference voltage,a scope of which is not limited herein.

The USB PD controller 110, in at least some examples, includes and/orimplements at least a portion of a VCONN control circuit 114. Forexample, when the USB PD controller 110 is a microcontroller, at least aportion of the VCONN control circuit 114 is implemented as particularprogramming within the USB PD controller 110 to perform at least some ofthe operations disclosed herein. In other examples, the VCONN controlcircuit 114 is implemented separately from the USB PD controller 110(e.g., as a separate microcontroller or other processing element) andconfigured to couple to the USB PD controller 110. In some examples, thesource device 102 further includes a transistor 116 operable as a switchto control output of the VBUS signal via a VBUS terminal 122 of thesource device 102 and a receptacle 124 configured to receive a plug toprovide communicative coupling with the source device 102. Thetransistor 116 may be of any suitable technology, including at leastp-type FET or n-type FET.

In at least one example architecture, an output of the power supply 108is coupled to a node 118, an input of the voltage control circuit 112 iscoupled to the node 118, a first terminal of the VCONN control circuit114 is coupled, or configured to couple, to the node 118, and a firstterminal (e.g., a drain terminal) of the transistor 116 is coupled tothe node 118. A first input of the voltage control circuit 112 iscoupled to a VREF output of the USB PD controller 110, and a firstoutput of the voltage control circuit 112 is coupled to a CATH input ofthe USB PD controller 110. A first terminal of the USB PD controller 110is coupled to a gate terminal of the transistor 116, a second terminalof the USB PD controller 110 is coupled to node 120, a second terminal(e.g., a source terminal) of the transistor 116 is coupled to node 120,and the VBUS terminal 122 is coupled to node 120. A second terminal ofthe VCONN control circuit 114 is configured to couple to a configurationchannel (CC1) terminal 132 and a third terminal of the VCONN controlcircuit 114 is configured to couple to a CC2 terminal 134. In variousexamples, CC1 and CC2 are each configurable to couple to a VCONNterminal 138 of the USB cable 104 or a CC terminal 136 of the USB cable104, depending on the orientation in which the plug 126 is inserted intothe receptacle 124. In some examples, the VBUS terminal 122, the CC1terminal 132, and the CC2 terminal 134 are housed in, are a part of, orotherwise interact with the receptacle 124 to communicatively couple thesource device 102 to the USB cable 104.

In at least one example, the USB cable 104 includes a plug 126configured to interact with the receptacle 124 to communicatively couplethe USB cable 104 to the source device 102. The plug 126 houses,includes, or otherwise interacts with a VBUS terminal 140, the CCterminal 136, and the VCONN terminal 138 each configured tocommunicatively couple the USB cable 104 to the source device 102. TheUSB cable 104 further includes a paddle card (e.g., a circuit board) 128configured to facilitate communication via the USB cable 104 and one ormore electrically conductive or optically transmissive wires 130 tofurther facilitate communication via the USB cable 104. The paddle card128 includes one or more electrical components, the scope of which isnot limited herein, including at least an e-marker 142. The e-marker142, in some examples, includes couplings to at least the CC terminal136 and the VCONN terminal 138.

The sink device 106 may be any device suitable for coupling to the USBcable 104 to receive power from the source device 102 and/or communicatedata with the source device 102 and the scope of the sink device 106,its hardware architecture, or its method of operation are not limitedherein. In at least some examples, the sink device 106 also implements aUSB controller substantially similar to the USB PD controller 110 and/orincludes functionality substantially similar to the VCONN controlcircuit 114.

In an example of operation of the system 100, after the source device102 (e.g., the USB PD controller 110) determines that a sink device 106has been connected to the source device 102 via the USB cable 104, theUSB PD controller 110 controls the power supply 108 to output a signalhaving voltage level specified by a control signal received by the powersupply 108. The USB PD controller 110 controls the power supply 108 tooutput the signal, for example, by controlling the voltage controlcircuit 112.

In at least some examples, the USB PD controller 110 applies pull-upsignals on both the CC1 terminal 132 and the CC2 terminal 134 andmonitors the value of the signal present at each of the CC1 terminal 132and the CC2 terminal 134. In some examples, each of the pull-up signalshas a substantially same voltage level. In other examples, each of thepull-up signals may have a different voltage level. For example, the USBPD controller 110 compares the value of the signal present at each ofthe CC1 terminal 132 and the CC2 terminal 134 to a threshold value todetermine whether it is less than a value of the pull-up signal (or someproportionate amount of the value of the pull-up signal). For example,the source device 102 may monitor the CC1 terminal 132 and/or the CC2terminal 134 for the presence of an Open state, a Rd-attached state, ora Ra-attached state. The Open state exists for a CCx terminal (e.g.,either of the CC1 terminal 132 or the CC2 terminal 134) when the valueof the signal present at that CCx terminal is above a first threshold(in one example, 1.6V). The Rd-attached state exists for a CCx terminalwhen the signal present at that CCx terminal is below the firstthreshold and above a second threshold (in one example, 0.25V). TheRa-attached state exists for a CCx terminal when the signal present atthat CCx terminal is below the second threshold.

In some examples, the USB PD controller 110 ignores the presence of theUSB cable 104 when the sink device 106 is not coupled to the USB cable104 (and thereby, the source device 102). For example, when the CCxterminal is in the Ra-attached state and a CCy terminal (e.g., either ofthe CC1 terminal 132 or the CC2 terminal 134 that is not the CCxterminal that is in the Ra-attached state) is in the Open state, the USBPD controller 110 ignores the presence of the USB cable 104 and does notcommunicate with the USB cable 104. In other examples, the USBcontroller 110 communicates with the USB cable 104 when the CCx terminalis in the Ra-attached state and the CCy terminal is in the Open state.

In at least some examples, when the USB PD controller 110 detects thepresence of the sink device 106, the USB PD controller 110 applies asignal to the VBUS terminal 122, for example, by controlling the powersupply 118 to output a voltage having a safe value for the e-marker 142(e.g., equal or approximately equal to a voltage specified foractivating the e-marker 142, such as 5V in some examples) andcontrolling the switch 116 to couple node 118 to VBUS terminal 122. Insome examples, the USB PD controller detects the presence of the sinkdevice 206 in one of two ways. First, when the CCx terminal is in theRd-attached state and the CCy terminal is in the Open state or theRa-Attached state, the USB PD controller 110 determines the sink device206 to be coupled to the source device 102. Second, when the CCxterminal is in the Open state or Ra-Attached state and the CCy terminalis in the Rd-attached state, the USB PD controller 110 also determinesthe sink device 206 to be coupled to the source device 102.

In at least some examples, when the sink device 106 is present and theCC1 terminal 132 or the CC2 terminal 134 is in the Ra-attached state,the USB cable 104 is an active cable that may contain the e-marker 142(though is not required to contain the e-marker 142). In at least someexamples, when the sink device 106 is present and the CC1 terminal 132or the CC2 terminal 134 is in the Open state, the USB cable 104 is apassive cable that does not contain the e-marker 142. When the USB PDcontroller 110 detects the sink device 106 is coupled to the sourcedevice 102 via the USB cable 104 when the USB cable 104 is an activecable, the USB PD controller 110 (or the VCONN control circuit 114)provides a signal to the VCONN terminal 138 while the power supply 108is outputting the voltage having the safe value for the e-marker 142. Inother examples, the USB PD controller 110 (or, or via, the VCONN controlcircuit 114) may provide the signal to the VCONN terminal 138 when theUSB cable 104 is a passive cable.

When the USB cable 104 is coupled to the source device 102 via plug 126and receptacle 124, the USB cable 104, when the USB cable 104 is anactive USB cable (e.g., such that the USB cable 104 includes thee-marker 142), loads or pulls down (e.g., such as via an approximately 1kilo-Ohm resistance) whichever of the CC1 terminal 132 or the CC2terminal 134 that is coupled to the VCONN terminal 138. Pulling down theone of the CC1 terminal 132 or the CC2 terminal 134 reduces the value ofthe signal present at the one of the CC1 terminal 132 or the CC2terminal 134 that is coupled to the VCONN terminal 138 and places thatone of the CC1 terminal 132 or the CC2 terminal 134 in the Ra-Attachedstate.

Similarly, when the source device 102 is coupled to the sink device 106(e.g., via the USB cable 104 utilizing plug 126 and receptacle 124), thesink device 106 loads or pulls down (e.g., such as via an approximately5.1 kilo-Ohm resistance) whichever of the CC1 terminal 132 or the CC2terminal 134 that is coupled to the CC terminal 136. Pulling down theone of the CC1 terminal 132 or the CC2 terminal 134 reduces the value ofthe signal present at the one of the CC1 terminal 132 or the CC2terminal 134 that is coupled to the CC terminal 136 and places that oneof the CC1 terminal 132 or the CC2 terminal 134 in the Rd-Attachedstate.

The VCONN control circuit 114 receives the output of the power supply108 at node 118 and controls transmission of an output on CC2 terminal134 based on a value of the voltage level of the output of the powersupply 108. For example, when the voltage level of the output of thepower supply 108 is equal or approximately equal to a voltage specifiedfor activating the e-marker 142 (e.g., such as approximately 5V), theVCONN control circuit 114 couples node 118 to CC2 terminal 134 fortransmission to the e-marker 142. In at least some examples, the VCONNcontrol circuit 114 includes a microcontroller (not shown) or otherprocessing element that monitors the value of the output of the powersupply 108 present at node 118 and outputs a control signal based onthat monitoring to couple node 118 to CC2 terminal 134. In someexamples, the microcontroller controls one or more switches (not shown)to couple node 118 to CC2 terminal 134. The switches are each anysuitable switching mechanism such as FETs, MOSFETs, BJTs, mechanicalswitches such as relays, and/or any other suitable switching technologyand/or architecture.

In at least some examples, when the USB PD controller 110 detects thatthe USB cable 104 is an active cable, after providing the signal to theVCONN terminal 138, the USB PD controller 110 (and/or the VCONN controlcircuit 114) communicates with the USB cable 104 (e.g., such as with thee-marker 142). The USB PD controller 110 communicates with the USB cable104, in some examples, to determine a maximum current rating of the USBcable 104 and/or other capabilities of the USB cable 104. In at leastsome examples, communication between the USB PD controller 110 and theUSB cable 104 occurs via the one of the CC1 terminal 132 or the CC2terminal 134 coupled to the CC terminal 136. In yet other examples, theUSB PD controller 110 may attempt to communicate with the USB cable 104without first determining whether the USB cable 104 is an active cable(e.g., such as by detecting the USB cable 104 loading one of the CC1terminal 132 or the CC2 terminal 134, as discussed above). In suchexamples, the USB PD controller 110 attempts to communicate with the USBcable 104 via the one of the CC1 terminal 132 or the CC2 terminal 134coupled to the CC terminal 136. If the USB PD controller 110 receives aresponse from the USB cable 104, operation proceed as further discussedherein. If the USB cable 104 does not respond, in some examples, the USBPD controller 110 proceeds under the assumption that the USB cable 104is a passive cable and assumes default and/or predefined capabilities ofthe USB cable 104.

After the USB PD controller 110 communicates (or attempts tocommunicate) with the USB cable 104, in some examples the USB controller110 begins communication with the sink device 106. In some examples,this communication causes, directly or indirectly, the value of thesignal present at node 118 to increase (or attempt to increase) beyondthe safe value for the e-marker 142. Accordingly, in at least someexamples, while node 118 is coupled to CC2 terminal 134, the USB PDcontroller 110 and/or the VCONN control circuit 114 preventscommunication from the source device 102 to the sink device 106 (e.g.,communication, such as (but not limited to) over the CC terminal thatmay involve or otherwise cause a change or variation in the value of thesignal present at node 118 and output via the VBUS terminal 122). Inother examples, while node 118 is coupled to CC2 terminal 134, the USBPD controller 110 and/or the VCONN control circuit 114 limitstransmissions from the source device 102 to the sink device 106 via theVBUS terminal 122 to transmissions occurring with a voltage valueapproximately equal to the voltage specified for activating the e-marker142. In some examples, the USB PD controller 110 and/or the VCONNcontrol circuit 114 decouples node 118 from CC2 terminal 134 when thesignal present at node 118 increases beyond the safe value for thee-marker 142. In yet other examples, the source device 102 includes avoltage regulator (not shown) such as a low-dropout regulator (LDO)coupled between the node 118 and the VCONN terminal 138 such that amaximum value of the voltage provided to the VCONN terminal 138 islimited by the voltage regulator without regard to the value of thesignal present at node 118. In some examples, the USB PD controller 110causes a value of the signal present at node 118 to increase. Forexample, the sink device 106 may request that the source device 102(e.g., via communication received via the USB PD controller 110) providea signal at node 118 (and therefore the VBUS terminal 122) having avalue greater than that of a currently provided signal. In response, theUSB controller 110 controls the voltage control circuit 112 (or,alternatively, directly controls the power supply 108) to modify a valueof the output of the power supply 108 provided to the node 118. The USBPD controller 110, in some examples, controls the voltage controlcircuit 112 based at least partially on generating and providing VREF tothe voltage control circuit 112.

While discussed herein and illustrated in FIG. 1 as the CC1 terminal 132being configured to couple to the CC terminal 136 and the CC2 terminal134 being configured to couple to the VCONN terminal 138, in someexamples the couplings may be reversed. For example, at least some USBcables 104 may be reversible such that, depending on an orientation withwhich the plug 126 is inserted into the receptacle 124, the CC1 terminal132 is configured to couple to one of the CC terminal 136 or the VCONNterminal 138 and the CC2 terminal 134 is configured to couple to theother of the CC terminal 136 or the VCONN terminal 138. Thus, whilecouplings associated with one orientation of insertion of the plug 126into the receptacle 124 are described herein, couplings associated withany orientation of insertion of the plug 126 into the receptacle 124 arecontemplated herein and encompassed within the scope of the presentdisclosure. Accordingly, in at least some examples, the USB PDcontroller 110 is further configured to detect and/or determine which ofCC1 terminal 132 or CC2 terminal 134 is coupled to the VCONN terminal138 (or to the CC terminal 136) to determine which of CC1 terminal 132or CC2 terminal 134 to couple to node 118.

Referring now to FIG. 2, a schematic diagram of a circuit 200 is shown.In at least one example, the circuit 200 is suitable for implementationas the VCONN control circuit 114 of FIG. 1, and reference is made toelements of FIG. 1 with respect to the couplings of circuit 200. In atleast one example, the circuit 200 includes a switch 202, a switch 204,a VCONN switch control circuit 206, an orientation control circuit 208,and a de-multiplexer 210. The switch 202 and the switch 204 are each anysuitable switching mechanism such as FETs, MOSFETs, BJTs, mechanicalswitches such as relays, and/or any other suitable switching technologyand/or architecture capable of supporting a maximum output voltage valueof the power supply 108, such as the maximum voltage value that would bepresent at the node 108. In at least one example, the VCONN switchcontrol circuit 206 is implemented as, or by, any suitable processingelement (such as a microprocessor) capable of performing the operationsdisclosed herein. In at least one example, the orientation controlcircuit 208 is implemented as, or by, any suitable processing element(such as a microprocessor) capable of performing the operationsdisclosed herein. In some examples, both the VCONN switch controlcircuit 206 and the orientation control circuit 208 are implemented bythe same processing element. In some examples, one or both of the VCONNswitch control circuit 206 and/or the orientation control circuit 208are implemented by the USB PD controller 110 of FIG. 1 (e.g., such thatthe USB PD controller 110 and the VCONN switch control circuit 206and/or the orientation control circuit 208 are implemented in the samemicrocontroller or processing element).

In one example architecture of the circuit 200, a first terminal of theswitch 202 is coupled to the node 118 of FIG. 1 and a second terminal ofthe switch 202 is coupled to a first terminal of the switch 204. Asecond terminal of the switch 204 is coupled to an input of thede-multiplexer 210. A first output of the VCONN switch control circuit206 is coupled to a control terminal of the switch 202 and a secondoutput of the VCONN switch control circuit 206 is coupled to a controlterminal of the switch 204. An output of the orientation control circuit208 is coupled to a selection input of the de-multiplexer 210.

In an example of operation of the circuit 200, the VCONN switch controlcircuit 206 monitors the CC1 terminal 132 and the CC2 terminal 134 todetermine whether the sink device 106 is coupled to the source device102. When the sink device 106 is coupled to the source device 102, insome examples, the VCONN control circuit 206 generates a first controlsignal for controlling the switch 202 and generates a second controlsignal for controlling the switch 204. In at least some examples,control of the switch 202 and the switch 204 is further based on a valueof the signal present at node 118 and, when the value of the signalpresent at node 118 is equal or approximately equal to a voltagespecified for activating the e-marker 142, the switch 202 and the switch204 are controlled to turn on. For example, the signal present at node118 may be compared to a threshold value and the switch 202 and theswitch 204 may be controlled to turn on or off based on both a result ofthe comparison (e.g., such as a an output of a comparator (not shown))and the first control signal and second control signal, respectively,output by the VCONN switch control circuit 206.

Additionally, the orientation control circuit 208 monitors the CC1terminal 132 and the CC2 terminal 134 to determine an orientation ofinsertion of the plug 126 into the receptacle 124, each of FIG. 1, andgenerates a selection control signal for controlling the de-multiplexer210. For example, the orientation control circuit 208 monitors the CC1terminal 132 and the CC2 terminal 134 to determine whether the sinkdevice 106 has been coupled to the source device 102 via the USB cable104 and the orientation of insertion of the plug 126 into the receptacle124 based on the sink device 106 being coupled to the source device 102via the USB cable 104. In at least some examples, the orientationcontrol circuit 208 determines the orientation of insertion of the plug126 into the receptacle 124 based on a value of a signal present at CC1terminal 132 and/or the CC2 terminal 134, for example, based on loadingof the CC1 terminal 132 and/or the CC2 terminal 134 as discussed abovewith respect to FIG. 1. By determining an amount of loading of the CC1terminal 132 or the CC2 terminal 134, the orientation control circuit208 determines the orientation of insertion of the plug 126 into thereceptacle 124 and which of the CC1 terminal 132 or the CC2 terminal 134is coupled to the VCONN terminal 138. Based on the orientation ofinsertion of the plug 126 into the receptacle 124 and which of the CC1terminal 132 or the CC2 terminal 134 is coupled to the VCONN terminal138, the orientation control circuit 208 generates a selection controlsignal and provides the selection control input to the selection inputof the de-multiplexer 210 to control output by the de-multiplexer 210.For example, when the orientation control circuit 208 provides thede-multiplexer 210 with a selection control signal having a value ofzero, the de-multiplexer 210 provides the signal received at the inputterminal of the de-multiplexer 210 to the CC2 terminal 134. Similarly,when the orientation control circuit 208 provides the de-multiplexer 210with a selection control signal having a value of one, thede-multiplexer 210 provides the signal received at the input terminal ofthe de-multiplexer 210 to the CC1 terminal 132.

Referring now to FIG. 3, a schematic diagram of a circuit 300 is shown.In at least one example, the circuit 300 is suitable for implementationas the VCONN control circuit 114 of FIG. 1, and reference is made toelements of FIG. 1 with respect to the couplings of circuit 300. In atleast one example, the circuit 300 includes a switch 302, a switch 304,a switch 306, a switch 308, and a VCONN switch and orientation controlcircuit 310. The switch 302, switch 304, switch 306, and switch 308 areeach any suitable switching mechanism such as FETs, MOSFETs, BJTs,mechanical switches such as relays, and/or any other suitable switchingtechnology and/or architecture capable of supporting a maximum outputvoltage value of the power supply 108, such as the maximum voltage valuethat would be present at the node 108. In at least one example, theVCONN switch and orientation control circuit 310 is implemented as, orby, any suitable processing element (such as a microprocessor) capableof performing the operations disclosed herein. In some examples, atleast some aspects of the VCONN switch and orientation control circuit310 are implemented by the USB PD controller 110 of FIG. 1 (e.g., suchthat the USB PD controller 110 and the VCONN switch and orientationcontrol circuit 310 are implemented in the same microcontroller orprocessing element). In some examples, the VCONN switch and orientationcontrol circuit 310 is implemented as multiple separate circuitsconfigured to couple together.

In one example architecture of the circuit 300, a first terminal of theswitch 302 is coupled to the node 118 of FIG. 1 and a second terminal ofthe switch 302 is coupled to a first terminal of the switch 304. Asecond terminal of the switch 304 is coupled to the CC2 terminal 134. Afirst terminal of the switch 306 is coupled to the node 118 and a secondterminal of the switch 306 is coupled to a first terminal of the switch308. A second terminal of the switch 308 is coupled to the CC1 terminal132. A first output of the VCONN switch and orientation control circuit310 is coupled to a control terminal of the switch 302, a second outputof the VCONN switch and orientation control circuit 310 is coupled to acontrol terminal of the switch 304, a third output of the VCONN switchand orientation control circuit 310 is coupled to a control terminal ofthe switch 306, and a fourth output of the VCONN switch and orientationcontrol circuit 310 is coupled to a control terminal of the switch 308.

In an example of operation of the circuit 300, the VCONN switch andorientation control circuit 310 monitors a value of the signal presentat node 118 and, based at least partially on the value of the signalpresent at node 118 being equal, or approximately equal, to a voltagespecified for activating the e-marker 142, generates control signals forcontrolling at least some of the switch 302, switch 304, switch 306,and/or switch 308. In some examples, the control signals control atleast some of the switch 302, switch 304, switch 306, and/or switch 308to turn on (e.g., conduct current), such as when the value of the signalpresent at node 118 being equal, or approximately equal, to the voltagespecified for activating the e-marker 142. In other examples, thecontrols signals control at least some of the switch 302, switch 304,switch 306, and/or switch 308 to turn off (e.g., not conduct current),such as when the value of the signal present at node 118 is not equal,or approximately equal, to the voltage specified for activating thee-marker 142. Additionally, the VCONN switch and orientation controlcircuit 310 monitors the CC1 terminal 132 and the CC2 terminal 134 todetermine an orientation of insertion of the plug 126 into thereceptacle 124, each of FIG. 1, and further generates the controlsignals for controlling at least some of the switch 302, switch 304,switch 306, and/or switch 308 based at least partially on the determinedorientation of insertion of the plug 126 into the receptacle 124. Forexample, the VCONN switch and orientation control circuit 310 monitorsthe CC1 terminal 132 and the CC2 terminal 134 to determine whether thesink device 106 has been coupled to the source device 102 via the USBcable 104 and the orientation of insertion of the plug 126 into thereceptacle 124 in a manner substantially similar to that of theorientation control circuit 208, discussed above with reference to FIG.2, the description of which is not repeated herein. Based on theorientation of insertion of the plug 126 into the receptacle 124, andwhich of the CC1 terminal 132 or the CC2 terminal 134 is coupled to theVCONN terminal 138, the orientation control circuit 310 generates one ormore control signals and provides the control signal(s) to switch 302and switch 304 or to switch 306 and 308, for example, to couple node 118to the VCONN terminal 138. For example, when the orientation controlcircuit 310 sends an enable signal to switch 302 and switch 304, node118 is coupled to the CC2 terminal 134 and the orientation controlcircuit 310 also sends a disable signal to switch 306 and switch 308 toprevent coupling node 118 to the CC1 terminal 132. Similarly, when theorientation control circuit 310 sends an enable signal to switch 306 andswitch 308 such that node 118 is coupled to the CC1 terminal 132 and theorientation control circuit 310 sends a disable signal to switch 302 andswitch 304 to prevent coupling node 118 to CC2 terminal 134.

Referring now to FIG. 4, a schematic diagram of a circuit 400 is shown.In at least one example, the circuit 400 is suitable for implementationas the VCONN control circuit 114 of FIG. 1, and reference is made toelements of FIG. 1 with respect to the couplings of circuit 400. In atleast one example, the circuit 400 includes a switch 402, a switch 404,and a VCONN switch and orientation control circuit 406. The switch 404and the switch 204 are each any suitable switching mechanism such asFETs, MOSFETs, BJTs, mechanical switches such as relays, and/or anyother suitable switching technology and/or architecture capable ofsupporting a maximum output voltage value of the power supply 108, suchas the maximum voltage value that would be present at the node 108. Inat least one example, the VCONN switch and orientation control circuit406 is implemented as, or by, any suitable processing element (such as amicroprocessor) capable of performing the operations disclosed herein.In some examples, at least some aspects of the VCONN switch andorientation control circuit 406 are implemented by the USB PD controller110 of FIG. 1 (e.g., such that the USB PD controller 110 and the VCONNswitch and orientation control circuit 406 are implemented in the samemicrocontroller or processing element). In some examples, the VCONNswitch and orientation control circuit 406 is implemented as multipleseparate circuits configured to couple together.

In one example architecture of the circuit 400, a first terminal (e.g.,drain terminal) of the switch 402 is coupled to the node 118 of FIG. 1and a second terminal (e.g., source terminal) of the switch 402 iscoupled to the CC2 terminal 134. A first terminal (e.g., drain terminal)of the switch 404 (for example the drain) is coupled to the node 118 anda second terminal (e.g., source terminal) of the switch 306 is coupledto the CC1 terminal 132. A first output of the VCONN switch andorientation control circuit 406 is coupled to a control terminal (e.g.,gate terminal) of the switch 402 and a second output of the VCONN switchand orientation control circuit 406 is coupled to a control terminal(e.g., gate terminal) of the switch 404.

In an example of operation of the circuit 400, the VCONN switch andorientation control circuit 406 monitors a value of the signal presentat node 118 and, based at least partially on the value of the signalpresent at node 118 being equal or approximately equal to a voltagespecified for activating the e-marker 142, generates control signals forcontrolling at least one of the switch 402 or the switch 404.Additionally, the VCONN switch and orientation control circuit 406monitors the CC1 terminal 132 and the CC2 terminal 134 to determine anorientation of insertion of the plug 126 into the receptacle 124, eachof FIG. 1, and further generates the control signals for controlling atleast some of the switch 402 or the switch 404 based at least partiallyon the determined orientation of insertion of the plug 126 into thereceptacle 124. For example, the VCONN switch and orientation controlcircuit 406 monitors the CC1 terminal 132 and the CC2 terminal 134 todetermine whether the sink device 106 has been coupled to the sourcedevice 102 via the USB cable 104 and the orientation of insertion of theplug 126 into the receptacle 124 in a manner substantially similar tothat of the orientation control circuit 208, discussed above withreference to FIG. 2, the description of which is not repeated herein.Based on the orientation of insertion of the plug 126 into thereceptacle 124, and which of the CC1 terminal 132 or the CC2 terminal134 is coupled to the VCONN terminal 138, the VCONN switch andorientation control circuit 406 generates one or more control signalsand provides the control signal(s) to either switch 402 or switch 404 tocouple 118 to VCONN 138. For example, when the VCONN switch andorientation control circuit 406 sends an enable signal to switch 402,node 118 is coupled to the CC2 terminal 134 and the VCONN switch andorientation control circuit 406 sends a disable signal to switch 404 toprevent coupling node 118 to CC1 terminal 132. Similarly, when the VCONNswitch and orientation control circuit 406 sends an enable signal toswitch 404, node 118 is coupled to the CC1 terminal 132 and the VCONNswitch and orientation control circuit 406 sends a disable signal toswitch 402 to prevent coupling node 118 to CC2 terminal 134. In someexamples, the circuit 400 consumes less power and has a reduced sizewhen compared to the circuit 300, for example, because the circuit 400includes fewer switches. In some examples of circuit 400, node 118 ismaintained at a voltage sufficiently higher than a voltage of the CC2terminal 134 when the switch 402 is disabled to prevent current fromflowing in the reverse direction. Similarly, in some examples, node 118is maintained at a voltage sufficiently higher than a voltage of the CC1terminal 132 when the switch 404 is disabled to prevent current fromflowing in the reverse direction.

Referring now to FIG. 5, a schematic diagram of a circuit 500 is shown.In at least one example, the circuit 500 is suitable for implementationas the voltage control circuit 112 of FIG. 1, and reference is made toelements of FIG. 1 with respect to the couplings of circuit 500. In atleast one example, the circuit 500 includes an optocoupler 505 (thatincludes a light emitting diode 506 and a photo-sensor 507), resistors510, 515, 530, 535, 540, 545, and 547, a shunt regulator 520, and acapacitor 525. In some examples, at least some aspects of the circuit500 are implemented in other devices. For example, at least somecomponents of the circuit 500, when implemented as the voltage controlcircuit 112, may be implemented in the USB PD controller 110.Additionally, in various examples, at least some components of circuit500 (e.g., the resistor 535) may be omitted or additional components notshown may be added to the circuit 500 to support the functionalitydescribed herein.

In at least one example architecture of circuit 500, the optocoupler 505has a first terminal coupled to a node 565 and configured to receive avoltage VDD used in generating an output of a power supply, a secondterminal coupled to node 570, a third terminal coupled to node 575 viaresistor 510, and a fourth terminal coupled to node 580. The resistor515 is coupled between node 575 and node 580. The shunt regulator 520has a cathode coupled to node 580, an anode coupled to a ground voltagepotential 550, and a control input coupled to node 585. The capacitor525 is coupled between node 580 and node 585. The resistor 530 iscoupled between node 555 and node 575, the resistor 535 is coupledbetween node 560 and node 585, the resistor 540 is coupled between node585 and the ground voltage potential 550, the resistor 545 is coupledbetween node 570 and the ground voltage potential 550, and the resistor547 is coupled between node 575 and node 585. In some examples, thecircuit 500 is configured to receive a power supply output (VSOURCE) atnode 555 (e.g., such that node 555 corresponds to node 118 of FIG. 1),receive VREF at node 560, receive CATH at node 580, and couple to acontrol input of the power supply (e.g., the power supply 108 of FIG. 1)at node 570.

In an example of operation of the circuit 500, the shunt regulator 520converts a voltage present at node 585 to a proportional current thatdrives a brightness of the light emitting diode 506 of the optocoupler505. The light emitted by the light emitting diode 506 is converted backto a proportional voltage by the photo-sensor 507, thereby approximatelyproviding a proportional voltage at node 570 to the voltage present atnode 585. When node 560 is floating, the resistor 547 and resistor 540create a voltage divider that establishes a voltage present at node 585as proportional to a voltage present at node 555. When current is sunkfrom node 560, the change in voltage at node 585 that is conveyed by theshunt regulator 520 and optocoupler 505 to node 570 causes a value ofVSOURCE to change proportional to a value of the current sunk from node560.

Referring now to FIG. 6, a timing diagram 600 of illustrative signals inaccordance with various examples is shown. The signals of diagram 600are illustrative of operation of at least one exemplary implementationof the system 100, discussed above with respect to FIG. 1. For example,at least some signals of the diagram 600 may be generate, monitored,and/or otherwise associated with at least one of the USB PD controller110 and/or the VCONN control circuit 114. Illustrated in FIG. 6 are aCC1 signal indicating a value of a signal present at CC1 terminal 132, aCC2 signal indicating a value of a signal present at the CC2 terminal134, a VCONN signal indicating a value of a signal present at VCONNterminal 138, a VBUS signal indicating a value of a signal output by thesystem 100 via the VBUS terminal 122, and a CC signal indicating a valueof a signal present at the CC terminal 136. Each signal of the diagram600 is representative in a vertical direction of voltage andrepresentative in a horizontal direction of time.

As shown in diagram 600, at a time t1, the CC1 terminal 132 and the CC2terminal 143 are in an open state, representing a pull-up voltageapplied to the CC1 terminal 132 and the CC2 terminal 143, for example,by the USB PD controller 110 and/or the VCONN control circuit 114. Alsoat the time t1, the VBUS terminal 122, CC terminal 136, and VCONNterminal 138 are each representative of a low signal (e.g.,approximately zero) because the USB cable 104 is not coupled to thesource device 102 at time t1.

At a time t2, the USB cable 104 is coupled to the source device 102,loading the CC2 terminal 134 and reducing the value of the signalpresent at the CC2 terminal 134. At a time t3, the sink device 106 iscoupled to the USB cable 104 (and thereby the source device 102),loading the CC1 terminal 132 and reducing the value of the signalpresent at the CC1 terminal 132. While discussed for the sake ofsimplicity of description with reference to diagram 600 as the USB cable104 loading the CC2 terminal 134 and the sink device 106 loading the CC1terminal 132, the inverse may also occur, for example, based on anorientation of insertion of plug 126 into receptacle 124, as discussedabove with reference to the preceding figures. Additionally, while timet2 and time t3 are discussed and illustrated as occurring sequentially,in some examples time t2 and time t3 may occur consecutively, such aswhen the USB cable 104 is coupled to the sink device 106 prior tocoupling the USB cable 104 to the source device 102.

At a time t4, a voltage is applied to the VBUS terminal 122 and the CC2terminal 134 (and therefore the VCONN terminal 138), for example, tofacilitate communication with the e-marker 142. The voltage is appliedby one or more of the USB PD controller 110 and/or the VCONN controlcircuit 114, for example, as described above with reference to thepreceding figures. A value of the voltage is, for example, a safe valuefor the e-marker 142 (e.g., equal or approximately equal to a valuespecified for activating the e-marker 142). Additionally, although notshown in diagram 600, in some examples a delay may exist betweenapplication of the voltage to the VBUS terminal 122 and the CC2 terminal134 such that one of the VBUS terminal 122 or the CC2 terminal 134receives the applied voltage before the other of the VBUS terminal 122or the CC2 terminal 134.

At a time t5, communication occurs between the USB PD controller 110 andthe e-marker 142 via the CC1 terminal 134 and the CC terminal 136. Thecommunication, in some examples, includes one or more start of packet(SOP) messages sent from the USB PD controller 110 to e-marker 142and/or one or more SOP messages sent from the e-marker 142 to the USB PDcontroller 110, for example, such that the USB PD controller 110determines capabilities of the e-marker 142. While t5 is illustrated inFIG. 6 as occurring subsequent to t4, in some examples, t5 may occursubstantially simultaneously with, or before, t4.

At a time t6, occurring subsequent to an end of the communication begunat time t5, the voltage applied at time t4 is removed from the CC2terminal 134 and therefore from the VCONN terminal 138. The voltage isremoved by one or more of the USB PD controller 110 and/or the VCONNcontrol circuit 114, for example, as described above with reference tothe preceding figures.

At a time t7, communication occurs between the USB PD controller 110 andthe sink device 106 via the CC1 terminal 134 and the CC terminal 136.The communication, in some examples, includes one or more SOP messagessent from the USB PD controller 110 to the sink device 106 and/or one ormore SOP messages sent from the sink device 106 to the USB PD controller110. The SOP messages include, in various examples, Source Capabilitiesmessages, Request messages, and/or Accept messages, as discussed herein.While t7 is illustrated in FIG. 6 as occurring subsequent to t6, in someexamples, t7 may occur substantially simultaneously with t6.

At a time t8, a voltage having a value greater than the safe value forthe e-marker 142 is applied to the VBUS terminal 122, for example,subsequent to, or to facilitate, communication with the sink device 106(such as a result of SOP messages received from the sink device 106requesting an increase to the value of the voltage provided to the VBUSterminal 122) and/or transmission of power to (e.g., charging of) thesink device 106 (e.g., via the VBUS terminal 122). The voltage isapplied, in some examples, by the USB PD controller 110, for example, asdescribed above with reference to the preceding figures. In someexamples, t6 and t8 occur substantially simultaneously such that, theVCONN control circuit 114 decouples the node 118 from the CC2 terminal134 (and therefore the VCONN terminal 138) when the voltage at node 118rises above a pre-defined value, such as the safe value for the e-marker142.

In at least some examples, the signals represented in FIG. 6 are notscaled to a same voltage value but the signals CC2 and VCONN havesubstantially a same value beginning at the time t2 and the signals CC1and CC have substantially a same value beginning at the time t3.

Referring now to FIG. 7, a flowchart of an illustrative method 700 inaccordance with various examples is shown. In some embodiments, themethod 700 illustrates a VCONN output method. Accordingly, in at leastsome examples, at least some aspects of the method 700 are implementedby a controller such as a USB PD controller (e.g., the USB PD controller110 of FIG. 1) and/or a VCONN control circuit such as any of the VCONNcontrol circuits 114 of FIG. 1, circuit 200 of FIG. 2, circuit 300 ofFIG. 3, or circuit 400 of FIG. 4.

At operation 705, the controller detects a coupling from a sink deviceto a source device. The controller detects the connection from the sinkdevice, in at least some examples, by detecting the sink device loadingat least one terminal coupled to the controller (e.g., via a couplingutilizing a USB cable). In some examples, the detections are at leastpartially performed by a processing element (e.g., such as amicrocontroller) monitoring one or more terminals coupled to thecontroller and determining that one of the one or more terminals isbeing loaded by the sink device based on one or more comparisons ofvalues present at, or viewed from, the one or more terminals by theprocessing element to known or expected values (e.g., such as one ormore threshold values), as described in greater detail above withrespect to FIG. 1.

At operation 710, the controller applies a signal to a VBUS terminalcoupled to the controller and a VCONN terminal coupled to thecontroller. The controller applies the signal to the VBUS terminal andthe VCONN terminal, in some examples, by controlling one or moreswitches to establish couplings between respective terminals of theswitches to establish a path between a power supply and the VBUSterminal and between the power supply and the VCONN terminal. In atleast some examples, each of the switches is a transistor. In someexamples, to apply the signal to the VBUS terminal, the controllergenerates and provides to one of the switches, a control signal having avalue sufficient to cause the switch to conduct current betweenrespective terminals of the switch. In some examples, to apply thesignal to the VCONN terminal, the controller generates at least oneadditional control signal and provides the control signal to another ofthe switches. The control signal is, for example, a signal having avalue sufficient to cause the switch to conduct current betweenrespective terminals of the switch. In at least one example, prior toapplying the signal to the VCONN terminal, the controller determineswhether a predefined amount of resistance is present at a node coupledto the VCONN terminal (e.g., such as a desired amount of resistance in apull-down resistor coupled to the node shared with the VCONN terminal).In some examples, the controller outputs a reference value to controlthe voltage level of the signal. In some examples, the controllerfurther determines which terminal coupled to the controller is the VCONNterminal based at least partially on the loading determined and/ordetected at operation 705.

At operation 715, the controller communicates with the USB cablecoupling the sink device to the source device. The controllercommunicates with the USB cable, in one example to interrogate or querythe USB cable to determine capabilities and/or specifications of the USBcable. In at least one example, the controller communicates with ane-marker of the USB cable, where the e-marker is powered via the signalapplied to the VCONN terminal. In at least some examples, the controllerlimits the value of the signal applied to the VCONN terminal to a safevalue for the e-marker (e.g., equal or approximately equal to a voltagespecified for activating the e-marker). In some examples, the controllercommunicates with the e-marker of the USB cable at least via a SOPmessage having a first or a second format (e.g., a SOP′ message or aSOP″ message) to determine capabilities, specifications, and/orlimitations of the USB cable.

At operation 720, after communicating with the USB cable and/ordetermining the capabilities, specifications, and/or limitations of theUSB cable the controller removes the signal from the VCONN terminal,thereby removing the power source from the e-marker. In some examples,to remove the signal from the VCONN terminal, the controller generatesat least one control signal and provides the control signal to one ofthe switches, where the signal does not have a value sufficient to causethe switch to conduct current between respective terminals of theswitch.

At operation 725, the controller communicates with the sink device viathe USB cable, at least partially according to the determinedcapabilities, specifications, and/or limitations of the USB cable. Insome examples, to communicate with the sink device, the controllertransmits one or more SOP messages having a third format (e.g., a SOPmessage) to the sink device via the USB cable. In some examples,operation 725 may be performed prior to, or concurrently with, operation720. In such examples, the controller prevents the signal provided tothe VBUS terminal and the VCONN terminal from exceeding the safe valuefor the e-marker until the signal is removed from the VCONN terminal. Insome examples, the controller limits the signal from exceeding the safevalue for the e-marker by advertising a source capability to the sinkdevice that specifies a capability of communicating a valueapproximately equal to, or less than, the safe value for the e-markerwhile the signal is applied to the VCONN terminal.

In some examples, when the controller communicates with the sink devicevia the USB cable (e.g., via a CC terminal of the USB cable), thecontroller transmits digital messages formed into packets. For example,the controller may send a Source Capabilities SOP message that indicatesone or more voltage values that the source device is capable ofoutputting (e.g., via a power supply of, or coupled to, the sourcedevice). The controller may further indicate in the Source CapabilitiesSOP message, an amount of current that the source device is capable ofproviding for each voltage. When the sink device receives the SourceCapabilities SOP message, the sink device may select a preferred voltagevalue and send a Request SOP message to the source device requesting thepreferred voltage value at a preferred current. In some examples, thesource device sends an Accept SOP message to the sink device andproceeds to control the power supply to output the preferred voltagevalue at the preferred current and provide the preferred voltage valueto the sink device via the VBUS terminal. In other examples, the sourcedevice indicates a maximum providable voltage value and a minimumprovidable voltage value in the Source Capabilities SOP message and thesink device indicates a specific voltage within that range in itsRequest SOP message.

In some examples, the source device (e.g., via the controller) restrictsthe voltage values indicated in the Source Capabilities SOP message. Forexample, prior to communicating with the cable, the source device maylimit the voltage values indicated in the Source Capabilities SOPmessage to those which are also safe values (e.g., safe voltage valuesfor the e-marker of the USB cable) that can be coupled to the VCONNterminal. Once communication between the source device (e.g., thecontroller) and the USB cable has ceased and the VCONN terminal isdecoupled from the power supply output, the source device may remove thelimitations on the voltage values offered to the sink device (e.g., asindicated in the Source Capabilities SOP message). In some examples, thesource device removes the limitations by the controller retransmittingthe Source Capabilities SOP message indicating all voltage values thatthe power supply is capable of generating, including those voltagevalues that would be unsafe for the USB cable (e.g., the e-marker) ifthe power supply output was still coupled to the VCONN terminal.

At operation 730, the controller increases a value of the signalprovided to the VBUS terminal beyond the safe value for the e-marker andbased at least partially on the determined capabilities, specifications,and/or limitations of the USB cable. In at least some examples, such asUSB-C cables, the controller increases the value of the signal providedto the VBUS terminal to greater than 5V, greater than 5.5V, greater than10V, greater than 15V, approximately 20V, or greater than 20V, the scopeof which is not limited herein. The controller increases the value ofthe signal provided to the VBUS terminal, in some examples, by varying avalue of a reference voltage (e.g., VREF) on which the value of thesignal provided to the VBUS terminal is at least partially based. Thereference voltage is provided, in some examples, to a circuit configuredto control or modify an output of a power supply, while in otherexamples the reference voltage is provided to the power supply.

While the operations of the method 700 have been discussed and labeledwith numerical reference, the method 700 may include additionaloperations that are not recited herein, any one or more of theoperations recited herein may include one or more sub-operations, anyone or more of the operations recited herein may be omitted, and/or anyone or more of the operations recited herein may be performed in anorder other than that presented herein (e.g., in a reverse order,substantially simultaneously, overlapping, etc.), all of which isintended to fall within the scope of the present disclosure.

In the foregoing discussion, the terms “including” and “comprising” areused in an open-ended fashion, and thus should be interpreted to mean“including, but not limited to . . . .” Also, the term “couple” or“couples” is intended to mean either an indirect or direct wired orwireless connection. Thus, if a first device, element, or componentcouples to a second device, element, or component, that coupling may bethrough a direct coupling or through an indirect coupling via otherdevices, elements, or components and connections. Similarly, a device,element, or component that is coupled between a first component orlocation and a second component or location may be through a directconnection or through an indirect connection via other devices,elements, or components and/or couplings. A device that is “configuredto” perform a task or function may be configured (e.g., programmedand/or hardwired) at a time of manufacturing by a manufacturer toperform the function and/or may be configurable (or re-configurable) bya user after manufacturing to perform the function and/or otheradditional or alternative functions. The configuring may be throughfirmware and/or software programming of the device, through aconstruction and/or layout of hardware components and interconnectionsof the device, or a combination thereof. Furthermore, a circuit ordevice that is said to include certain components may instead beconfigured to couple to those components to form the described circuitryor device. For example, a structure described as including one or moresemiconductor elements (such as transistors), one or more passiveelements (such as resistors, capacitors, and/or inductors), and/or oneor more sources (such as voltage and/or current sources) may insteadinclude only the semiconductor elements within a single physical device(e.g., a semiconductor die and/or integrated circuit (IC) package) andmay be configured to couple to at least some of the passive elementsand/or the sources to form the described structure either at a time ofmanufacture or after a time of manufacture, for example, by an end-userand/or a third-party.

While certain components are described herein as being of a particularprocess technology (e.g., FET, MOSFET, n-type, p-type, etc.), thesecomponents may be exchanged for components of other process technologies(e.g., replace FETE and/or MOSFET with bi-polar junction transistor(BJT), replace n-type with p-type or vice versa, etc.) and reconfiguringcircuits including the replaced components to provide desiredfunctionality at least partially similar to functionality availableprior to the component replacement. Additionally, uses of the phrase“ground voltage potential” in the foregoing discussion are intended toinclude a chassis ground, an Earth ground, a floating ground, a virtualground, a digital ground, a common ground, and/or any other form ofground connection applicable to, or suitable for, the teachings of thepresent disclosure. Unless otherwise stated, “about,” “approximately,”or “substantially” preceding a value means +/−10 percent of the statedvalue.

The above discussion is meant to be illustrative of the principles andvarious examples of the present disclosure. Numerous variations andmodifications will become apparent to those skilled in the art once theabove disclosure is fully appreciated. It is intended that the presentdisclosure be interpreted to embrace all such variations andmodifications.

What is claimed is:
 1. A process comprising: detecting, by a controller,a coupling from a sink device to a source device; applying, by thecontroller, signals to a bus voltage (VBUS) terminal and a connectorvoltage (VCONN) terminal of a cable performing the coupling;communicating, by the controller, with the cable performing the couplingto determine characteristics of the cable; removing, by the controller,the signal from the VCONN terminal; communicating, by the controller,with the sink device according to the characteristics of the cable; andincreasing, by the controller, a value of the signal provided to theVBUS terminal beyond an acceptable limit for providing to the VCONNterminal.
 2. The process of claim 1 in which the acceptable limit forproviding to the VCONN terminal is a voltage specified for activating anelectronic marker of the cable.
 3. The process of claim 1 in whichapplying the signal to the VBUS terminal and the VCONN terminal of thecable includes generating one or more switch control signals andcontrolling one or more switches according to the one or more switchcontrol signals.
 4. The process of claim 1 including preventing, by thecontroller, communication of a signal having a value beyond theacceptable limit for providing to the VCONN terminal to the sink devicevia the cable while the signal is applied to the VBUS terminal and theVCONN terminal.
 5. A process of operating a Universal Serial Bus PowerDelivery source device comprising: detecting in a controller coupling ofa sink device to receptacle terminals of the source device with a cablethat contains an e-marker device; coupling e-marker device communicationvoltages from a power source to a bus voltage (VBUS) terminal and aconnector voltage (VCONN) terminal of the receptacle; communicatingbetween the controller and the e-marker device for determiningcharacteristics of the cable; removing the voltage from the VCONNterminal after the determining; communicating between the controller andthe sink device according to the characteristics of the cable; andincreasing a value of the voltages provided to the VBUS terminal beyondan acceptable limit for providing voltages to the VCONN terminal.
 6. Theprocess of claim 5 in which the acceptable limit for providing voltageto the VCONN terminal is a voltage specified for activating the e-markerof the cable.
 7. The process of claim 5 in which the coupling voltagesto the VBUS terminal and the VCONN terminal of the cable includesgenerating one or more switch control signals and controlling one ormore switches according to the one or more switch control signals. 8.The process of claim 5 including preventing communication to the sinkdevice via the cable while the e-marker device communication voltagesare applied to the VBUS terminal and the VCONN terminal.
 9. The processof claim 5 in which the coupling includes adjusting a voltage from thepower supply.
 10. The process of claim 5 in which the coupling includesadjusting a voltage from the power supply in response to a controlsignal from the controller.
 11. The process of claim 5 in which theincreasing includes adjusting a voltage from the power supply.
 12. Theprocess of claim 5 in which the increasing includes adjusting a voltagefrom the power supply in response to a control signal from thecontroller.
 13. The process of claim 5 in which the detecting includesapplying pullup voltages to both a CC1 terminal and a CC2 terminal ofthe receptacle.
 14. The process of claim 5 in which the detectingincludes applying pullup voltages to both a CC1 terminal and a CC2terminal of the receptacle and monitoring a voltage value on the CC1 andCC2 terminals.
 15. The process of claim 14 in which the monitoringincludes comparing a voltage at a CC1 terminal and a voltage at a CC2terminal of the receptacle to a threshold.
 16. The process of claim 15in which the monitoring includes determining an Open state, aRd-attached state, and a Ra-attached state.